System for cleaning on-vehicle optical sensor and method for the same

ABSTRACT

The on-vehicle optical sensor cleaning system includes a washer pump that feeds a cleaning liquid, an air pump, a nozzle member, and a controller. The air pump includes a discharge valve and discharges air through the discharge valve. The discharge valve opens when air is compressed in the air pump. The nozzle member includes an ejection port that ejects a gas-liquid mixture toward a sensing surface of an on-vehicle optical sensor to remove foreign matter from the sensing surface. The cleaning liquid from the washer pump and the air from the air pump are mixed in the gas-liquid mixture. The controller controls the washer pump and the air pump. The controller is configured so that the gas-liquid mixture is ejected by storing the cleaning liquid in the nozzle member to cover the ejection port and then feeding the air to the nozzle member.

BACKGROUND

The present invention relates to a system for cleaning an on-vehicleoptical sensor and a method for cleaning an on-vehicle optical sensor.

Recent vehicles often include on-vehicle optical sensors at the front orrear to use the images captured by the on-vehicle optical sensors.Foreign matter such as mud may collect on a sensing surface (e.g., lensor protection glass) of an on-vehicle optical sensor. Thus, for example,Japanese Laid-Open Patent Publication No. 2001-171491 proposes anon-vehicle optical sensor cleaning system that ejects water and airhaving high pressure (water/compressed air) from a nozzle toward thesensing surface to remove the foreign matter.

Although the on-vehicle optical sensor cleaning system such as thatdescribed above uses a compressed air generating unit, there is nospecific mention of how high-pressure cleaning liquid (water) isejected. There is a demand for a technique for ejecting the cleaningliquid under higher pressure to increase the cleaning effect.

SUMMARY

It is an object of the present invention to provide an on-vehicleoptical sensor cleaning system and an on-vehicle optical sensor cleaningmethod that are capable of ejecting a gas-liquid mixture, in which acleaning liquid and air are mixed, under higher pressure.

To achieve the above object, one aspect of the present invention is anon-vehicle optical sensor cleaning system that includes a washer pumpthat feeds a cleaning liquid, an air pump, a nozzle member, and acontroller. The air pump includes a discharge valve and discharges airthrough the discharge valve. The discharge valve opens when air iscompressed in the air pump. The nozzle member includes an ejection portthat ejects a gas-liquid mixture toward a sensing surface of anon-vehicle optical sensor to remove foreign matter from the sensingsurface. The cleaning liquid from the washer pump and the air from theair pump are mixed in the gas-liquid mixture. The controller controlsthe washer pump and the air pump. The controller is configured so thatthe gas-liquid mixture is ejected by storing the cleaning liquid in thenozzle member to cover the ejection port and then feeding the air to thenozzle member.

Another aspect of the present invention is a method for cleaning anon-vehicle optical sensor that ejects a gas-liquid mixture in which acleaning liquid and air are mixed toward a sensing surface of theon-vehicle optical sensor to remove foreign matter from the sensingsurface. The method includes storing a cleaning liquid in a nozzlemember to cover an ejection port of the nozzle member, and then feedingair to the nozzle member to eject the gas-liquid mixture.

Other aspects and advantages of the invention will become apparent fromthe following description, taken in conjunction with the accompanyingdrawings, illustrating by way of example the principles of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with objects and advantages thereof, may best beunderstood by reference to the following description of the presentlypreferred embodiments together with the accompanying drawings in which:

FIG. 1A is a schematic diagram showing the structure of a firstembodiment of a vehicle according to the present invention;

FIG. 1B is a schematic view of the display shown in FIG. 1A;

FIG. 2 is a cross-sectional view of the on-vehicle optical sensor unitshown in FIG. 1A;

FIG. 3 is a perspective view of the on-vehicle optical sensor unit shownin FIG. 1A;

FIG. 4 is a front view of the on-vehicle optical sensor unit shown inFIG. 3;

FIG. 5 is a rear view of the on-vehicle optical sensor unit shown inFIG. 3;

FIG. 6 is a perspective cross-sectional view of the on-vehicle opticalsensor attachment bracket shown in FIG. 3;

FIG. 7 is a cross-sectional view showing a lower portion of theon-vehicle optical sensor attachment bracket shown in FIG. 6;

FIG. 8 is a cross-sectional view showing an upper portion of theon-vehicle optical sensor attachment bracket shown in FIG. 6;

FIG. 9A is an exploded perspective view of a piston unit;

FIG. 9B is an exploded perspective view of an intake housing member;

FIG. 9C is an exploded perspective view of a nozzle unit;

FIG. 9D is a perspective view of the nozzle unit;

FIG. 10 is a cross-sectional view of the nozzle unit arranged in anon-cleaning position;

FIG. 11 is a cross-sectional view showing the operation of the nozzleunit;

FIG. 12 is a cross-sectional view of an air pump;

FIGS. 13A and 13B are partially enlarged cross-sectional views showingthe operation of the air pump;

FIG. 14 is a time chart showing the operation of a washer pump and theair pump;

FIG. 15 is a cross-sectional view showing a portion of a modifiedexample of the nozzle unit of the first embodiment;

FIG. 16 is a cross-sectional view showing a portion of a modifiedexample of the nozzle unit of the first embodiment;

FIG. 17A is a schematic diagram showing the structure of a secondembodiment of a vehicle according to the present invention;

FIG. 17B is a schematic view of the display shown in FIG. 17A;

FIG. 18 is a perspective view of the on-vehicle optical sensor unitshown in FIG. 17A;

FIG. 19 is a perspective view of the on-vehicle optical sensor unitshown in FIG. 17A;

FIG. 20 is a cross-sectional view of the on-vehicle optical sensor unitshown in FIG. 18;

FIG. 21 is a cross-sectional view of a nozzle unit;

FIG. 22 is an exploded perspective view of a distal nozzle member and anozzle tip;

FIG. 23 is a cross-sectional view showing a portion of the nozzle unit;

FIG. 24 is a cross-sectional view showing a portion of the nozzle unit;and

FIG. 25 is an enlarged cross-sectional view showing a portion of theon-vehicle optical sensor unit.

DESCRIPTION OF THE EMBODIMENTS

A first embodiment of a vehicle will now be described with reference toFIGS. 1 to 14.

As shown in FIG. 1A, a rear door 2 is located on the rear of a vehicle1, and an on-vehicle optical sensor unit 3 is arranged on the rear door2. The on-vehicle optical sensor unit 3 of the first embodiment is fixedto a position located slightly toward a driver seat side (right side)from a lateral center line C of the vehicle 1.

As shown in FIGS. 2 to 5, the on-vehicle optical sensor unit 3 includesan on-vehicle camera 5, which functions as an on-vehicle optical sensor,a nozzle unit 6, which functions as an on-vehicle optical sensorcleaning device, and an on-vehicle optical sensor attachment bracket 7.

As shown in FIG. 2, the on-vehicle camera 5 includes a cuboid body 5 a,which accommodates an image capturing element (not shown), and a lens 5b, which is located on one surface of the body 5 a and functions as asensing surface (external image capturing surface).

As shown in FIGS. 1A and 1B, for example, when a shift lever SL of agearshift device is operated to a reverse position, the on-vehiclecamera 5 transmits a captured image of a rear side of the vehicle 1 toan in-vehicle display DSP to show the image. The on-vehicle camera 5 isfixed to the rear door 2 by the on-vehicle optical sensor attachmentbracket 7 so that the lens 5 b faces obliquely downward to capture anoblique downward image of the rear side of the vehicle 1.

As shown in FIGS. 2, 9D, 10, and 11, the entire contour of the nozzleunit 6 is cylindrical. The nozzle unit 6 includes a nozzle member 9including ejection ports 8. When moved from a non-cleaning position(refer to FIGS. 2 and 10) to a cleaning position (refer to FIG. 11), thenozzle member 9 projects outward and ejects a fluid from the ejectionports 8 toward the lens 5 b (refer to FIG. 2). In the presentembodiment, the fluid is one of a cleaning liquid, air, and a gas-liquidmixture.

As shown in FIG. 2, the on-vehicle optical sensor attachment bracket 7is integrally formed by a sensor receptacle 7 a, which accommodates theon-vehicle camera 5 and exposes the lens 5 b to the exterior, a nozzlereceptacle 7 b, which accommodates the nozzle unit 6, and a vehiclefastening portion 7 c.

More specifically, the on-vehicle optical sensor attachment bracket 7includes a tetragonal tube 7 d that includes an interior defining thesensor receptacle 7 a, which accommodates the cuboid on-vehicle camera5, and a circular tube 7 e that includes an interior defining the nozzlereceptacle 7 b, which accommodates the cylindrical nozzle unit 6. Thetetragonal tube 7 d and the circular tube 7 e are located beside eachother with side walls joined together. More specifically, the tetragonaltube 7 d includes a distal portion provided with a circular exposurebore 7 f that exposes the lens 5 b of the on-vehicle camera 5 to theexterior and a basal portion that opens to receive the on-vehicle camera5. The circular tube 7 e includes a distal portion provided with anozzle bore 7 g that is continuous with the exposure bore 7 f and allowsthe nozzle member 9 to move frontward and rearward and a basal portionthat opens to receive the nozzle unit 6. The circular tube 7 e isinclined relative to the tetragonal tube 7 d so that the circular tube 7e is located closer to the tetragonal tube 7 d as extending toward thedistal side. The circular tube 7 e (nozzle receptacle 7 b) is located ata driver seat side (right side) of the tetragonal tube 7 d (sensorreceptacle 7 a) in the lateral direction of the vehicle 1 (refer to FIG.1A).

As shown in FIGS. 2 and 5, a fastening member 11 is fastened to theon-vehicle optical sensor attachment bracket 7 by screws 12. Theon-vehicle camera 5, which is accommodated in the sensor receptacle 7 a,includes a rear end that engages with the fastening member 11. Thisprevents removal of the on-vehicle camera 5 from the sensor receptacle 7a and fixes the on-vehicle camera 5 to the on-vehicle optical sensorattachment bracket 7.

The nozzle unit 6, which is accommodated in the nozzle receptacle 7 b,includes fastening portions 13 that project out of the nozzle receptacle7 b. The fastening portions 13 are fastened to the on-vehicle opticalsensor attachment bracket 7 by screws 14. This prevents removal of thenozzle unit 6 from the nozzle receptacle 7 b.

As shown in FIG. 2, the on-vehicle optical sensor attachment bracket 7of the present embodiment includes liquid release portions 7 j, 7 k atlocations corresponding to the ejection ports 8 of the nozzle member 9when located at the non-cleaning position. The liquid release portions 7j, 7 k are cavities capable of receiving the cleaning liquid leaked fromthe ejection ports 8. The sensor receptacle 7 a and the nozzlereceptacle 7 b are in communication with each other, that is, apartition wall is not formed, at locations corresponding to the ejectionports 8. This forms the liquid release portions 7 j, 7 k in the sensorreceptacle 7 a and the nozzle receptacle 7 b. More specifically, whenthe cleaning liquid is leaked from the ejection ports 8 of the nozzlemember 9 when located at the non-cleaning position, the cleaning liquidmay flow into the liquid release portions 7 j, 7 k, which are formed inthe sensor receptacle 7 a and the nozzle receptacle 7 b.

As shown in FIGS. 6 and 7, the liquid release portions 7 j, 7 k areprovided with discharge bores 7 m, 7 n that open in directions differentfrom the exposure bore 7 f (lens 5 b). In the present embodiment, thedischarge bores 7 m, 7 n are open in the gravitational direction(downward). In the present embodiment, the discharge bore 7 mcorresponds to the liquid release portion 7 j of the sensor receptacle 7a, and the discharge bores 7 n correspond to the liquid release portion7 k of the nozzle receptacle 7 b.

As shown in FIGS. 6 and 7, the discharge bore 7 m of the sensorreceptacle 7 a includes an inner rim including an inclined surface 7 pat a location corresponding to a distal end of the on-vehicle camera 5.The inclined surface 7 p enlarges a gap (i.e., liquid release portion 7j) between the on-vehicle camera 5 and the on-vehicle optical sensorattachment bracket 7 and guides the cleaning liquid, which is leakedinto the liquid release portion 7 j, to the discharge bore 7 m.

As shown in FIG. 3, the discharge bore 7 m of the sensor receptacle 7 aincludes an outer rim including inclined surfaces 7 q on two ends atlocations corresponding to the distal end of the on-vehicle camera 5.The inclined surfaces 7 q facilitate discharging of the cleaning liquid,which is guided to the discharge bore 7 m in the liquid release portion7 j, out of the sensor receptacle 7 a from the discharge bore 7 m. Theinclined surfaces 7 q are arranged to extend in the gravitationaldirection.

As shown in FIG. 8, the nozzle receptacle 7 b includes an upper portionincluding a rotation restricting portion 16. The rotation restrictingportion 16 is a groove that engages with a projected rotation restrictedportion 15 (refer to FIG. 9D), which will be described later, in acircumferential direction.

The vehicle fastening portion 7 c is flange-shaped and projects from thebasal portions of the tetragonal tube 7 d and the circular tube 7 e. Thevehicle fastening portion 7 c is provided with fastening holes 7 r andfastened to the vehicle 1 by fastening pins (not shown) when insertedthrough the fastening holes 7 r.

As shown in FIGS. 2 and 9 to 11, the nozzle unit 6 includes an elongatedtubular cylinder housing 21, a piston unit 28, and an intake housingmember 22.

As shown in FIGS. 9C and 9D, the cylinder housing 21 has the form of anelongated tube and includes an outer circumferential surface. Therotation restricted portion 15 projects from the outer circumferentialsurface and engages with the rotation restricting portion 16 (refer toFIG. 8) in the circumferential direction. Additionally, a tubularelastic member R is fitted onto the outer circumference of the cylinderhousing 21. When accommodated in the nozzle receptacle 7 b, the cylinderhousing 21 is in press contact with an inner surface of the nozzlereceptacle 7 b with the elastic member R located in between.Additionally, a holder support 21 a extends radially inward from adistal portion of the cylinder housing 21 and engages with a springholder 23 (refer to FIGS. 2, 9A, and 9C), which will be described later.

As shown in FIGS. 9A and 10, the piston unit 28 includes the nozzlemember 9 and a compression coil spring 27. The nozzle member 9 includesa piston nozzle member 24 and a flange member 25. The piston nozzlemember 24 includes an elongated tube 24 a and a nozzle 24 b. The nozzle24 b is bulged from a distal portion of the tube 24 a to a radiallyouter side. The nozzle 24 b includes a distal end that defines theejection ports 8. The flange member 25 is fixed to a basal end of thepiston nozzle 24. In the present embodiment, the piston nozzle member 24of the nozzle member 9 includes a distal interior (interior of ejectionports 8) defining a common intake chamber D capable of drawing in thecleaning liquid and air. The flange member 25 includes an outer fittingtube 25 a, which is fitted onto a basal portion of the tube 24 a, and abasal flange 25 b, which projects radially outward from a basal portionof the outer fitting tube 25 a.

As shown in FIG. 10, the basal flange 25 b includes a packing fittingrecess 25 c that extends throughout the circumference and opens radiallyoutward. A lip packing 26 is fitted to the packing fitting recess 25 c.The lip packing 26 includes an annular fitting portion 26 a, a lipportion 26 b, and an annular slide portion 26 c. The fitting portion 26a is fitted to the packing fitting recess 25 c. The lip portion 26 baxially extends from a radially outer end of the fitting portion 26 atoward the basal side. The slide portion 26 c projects from a distalouter circumferential surface of the lip portion 26 b and has anarc-shaped cross section. The slide portion 26 c slides on an innercircumferential surface of the cylinder housing 21. Additionally, thepacking fitting recess 25 c of the present embodiment includesseparation restriction grooves 25 d that axially extend. The separationrestriction grooves 25 d of the present embodiment annually extend intwo axial surfaces of the packing fitting recess 25 c along the packingfitting recess 25 c. The fitting portion 26 a of the lip packing 26includes a pair of separation restriction projections 26 e, which arefitted to the separation restriction grooves 25 d.

The piston unit 28 includes the nozzle member 9, the spring holder 23coupled to the nozzle member 9, and the compression coil spring 27. Thespring holder 23, which is fitted onto the tube 24 a, allows axialsliding of the tube 24 a and restricts relative axial rotation of thetube 24 a. The compression coil spring 27 is fitted onto the tube 24 aand held in a compressed state between the spring holder 23 and thebasal flange 25 b. More specifically, the piston unit 28 is formed byfitting the spring holder 23 and the compression coil spring 27 onto thepiston nozzle member 24 from a basal end of the tube 24 a and thenfitting the outer fitting tube 25 a of the flange member 25 onto thebasal portion of the tube 24 a.

The cylinder housing 21 is configured to accommodate the piston unit 28.When coupling the piston unit 28, which has been assembled, the pistonunit 28 is inserted into the cylinder housing 21 from a basal end of thecylinder housing 21. The nozzle 24 b projects out of the distal portionof the cylinder housing 21. The spring holder 23 engages with the holdersupport 21 a located on the distal portion of the cylinder housing 21 torestrict further movement of the spring holder 23. As shown in FIGS. 9Aand 10, the spring holder 23 includes a discoid portion 23 a having alarger diameter than the holder support 21 a located on the distalportion of the cylinder housing 21. This restricts removal of the springholder 23 from the distal portion of the cylinder housing 21. The springholder 23 includes an engagement portion 23 b that is fitted in theholder support 21 a and circumferentially engaged with the holdersupport 21 a. This restricts rotation of the spring holder 23 relativeto the cylinder housing 21. The above arrangement allows the nozzlemember 9 to move frontward and rearward while accommodated in thecylinder housing 21. When the basal flange 25 b is urged toward theejection ports 8 by feeding pressure of a fluid, the nozzle member 9moves frontward against the urging force of the compression coil spring27 to the cleaning position (refer to FIG. 11). When the feedingpressure is not applied, the nozzle member 9 moves rearward to thenon-cleaning position due to the urging force of the compression coilspring 27.

The intake housing member 22 is coupled to a basal portion of thecylinder housing 21.

As shown in FIGS. 9B and 10, the intake housing member 22 includes aninlet member 31, an intake member 32, a cleaning-liquid-side check valve33, and an air-side check valve 34.

The inlet member 31 includes a tubular outer fitting portion 31 a, abasal flow passage 31 b, an inner extension 31 c, and a tubular inlet 31d. The outer fitting portion 31 a is fitted onto the basal portion ofthe cylinder housing 21. The basal flow passage 31 b axially extendsfrom a basal part of the outer fitting portion 31 a. The inner extension31 c inwardly extends from the basal part of the outer fitting portion31 a. The inlet 31 d extends from the inner extension 31 c to a sideopposite to the basal flow passage 31 b. The basal flow passage 31 b hasthe form of an oblong tube formed by parallel lines and arcs connectedto the parallel lines as viewed in the extension direction (axialdirection). As shown in FIG. 10, the inner extension 31 c is inclined topart from the basal flow passage 31 b as extending inward. The cylinderhousing 21 is provided with space SP between the inner extension 31 cand the basal flange 25 b. The outer diameter of the inlet 31 d is setslightly smaller than the inner diameter of the tube 24 a so that theinlet 31 d is loosely fitted to an inner surface of the tube 24 a wheninserted from the basal end of the nozzle member 9. The basal part ofthe outer fitting portion 31 a of the inlet member 31 includes thefastening portions 13 (refer to FIG. 5), which are fastened to theon-vehicle optical sensor attachment bracket 7 by the screws 14.

The intake member 32 includes an outer fitting portion 32 a, a tubularcleaning liquid intake passage 32 c, and an air intake passage 32 d. Theouter fitting portion 32 a is fitted onto the basal flow passage 31 b ofthe inlet member 31 and includes a basal closed end 32 b. The cleaningliquid intake passage 32 c and the air intake passage 32 d extend fromthe closed end 32 b parallel to the axial direction. More specifically,the outer fitting portion 32 a has the form of an oblong tube inconformance with the oblong tubular basal flow passage 31 b and may befitted onto the basal flow passage 31 b. The closed end 32 b has theform of an oblong disc. The closed end 32 b is provided with an air-sidethrough portion 32 e at a location corresponding to the axial center ofone of the arcs of the basal flow passage 31 b. The air intake passage32 d is in linear communication with the air-side through portion 32 e.Additionally, the closed end 32 b is provided with acleaning-liquid-side through portion 32 f at a location corresponding tothe axial center of the other arc of the basal flow passage 31 b. Thecleaning liquid intake passage 32 c is displaced toward an outer side ofthe cleaning-liquid-side through portion 32 f (in FIG. 10, side oppositeto air intake passage 32 d) and in communication with thecleaning-liquid-side through portion 32 f. Thus, while the distancebetween the cleaning liquid intake passage 32 c and the air intakepassage 32 d is long enough to connect a cleaning liquid hose H1 and anair hose H2, the distance between the cleaning-liquid-side throughportion 32 f and the air-side through portion 32 e is short. Thisreduces the size of the basal flow passage 31 b of the inlet member 31and the outer fitting portion 32 a of the intake member 32. Thecleaning-liquid-side check valve 33 is located at a position thatcommunicates to the cleaning-liquid-side through portion 32 f in thebasal flow passage 31 b of the inlet member 31 between the cleaningliquid intake passage 32 c and the common intake chamber D. The air-sidecheck valve 34 is located at a position that communicates to theair-side through portion 32 e in the basal flow passage 31 b of theinlet member 31 between the air intake passage 32 d and the commonintake chamber D. Each of the cleaning-liquid-side check valve 33 andthe air-side check valve 34 of the present embodiment is of aduckbill-type and includes a downstream portion (portion located towardcommon intake chamber D) having a squeezed opening. This allows for adownstream flow of a fluid and blocks an upstream flow of the fluid.

As shown in FIG. 10, the cleaning liquid intake passage 32 c isconnected to a washer pump WP by the cleaning liquid hose H1. The airintake passage 32 d is connected to an air pump AP by the air hose H2.

As shown in FIG. 1A, the washer pump WP is capable of feeding thecleaning liquid, which is a fluid stored in a tank T. When an internalpump motor (not show) is driven, the cleaning liquid is fed to (drawnin) the nozzle unit 6 (more specifically, cleaning liquid intake passage32 c) through the cleaning liquid hose H1.

The air pump AP is capable of instantaneously discharging compressedhigh-pressure air. When driven, air is fed to (drawn in) the nozzle unit6 (more specifically, air intake passage 32 d) through the air hose H2.

As shown in FIG. 12, the air pump AP of the present embodiment is apositive displacement pump and discharges air having a fixed volume. Theair pump AP includes an elongated tubular cylinder 41, a piston 42movable forward and backward in the cylinder 41, and a motor 43 locatedat a backward movement side of the piston 42 (left side in FIG. 12). Themotor 43 drives the piston 42 forward and backward.

As shown in FIGS. 13A and 13B, the air pump AP includes a dischargevalve 45 and a suction valve 47. The discharge valve 45 performs anopening operation and a closing operation to open and close a dischargevalve port 44 that communicates inner and outer sides of the cylinder41. The suction valve 47 performs an opening operation and a closingoperation to open and close suction valve ports 46 that communicateinner and outer sides of the piston 42. The discharge valve 45 openswhen the air is compressed in the air pump AP to predetermined pressure.More specifically, the piston 42 includes an operation member 67, whichwill be described later, and the discharge valve 45 includes anoperation projection 53. When the operation member 67 pushes theoperation projection 53, the discharge valve 45 opens. When the piston42 moves forward to reduce space (pump chamber P) in the cylinder 41,the air is compressed in the cylinder 41. Subsequently, the dischargevalve 45 opens and discharges the compressed air from the dischargevalve port 44. When the piston 42 moves backward, the suction valve 47opens and draws air into the cylinder 41 from the suction valve ports46.

More specifically, the cylinder 41 is tubular and has a closed enddefining a closed end 41 a (right end in FIG. 13). The closed end 41 aincludes a central portion provided with a central hole 41 b. Thecentral hole 41 b includes an outer opening defining the discharge valveport 44. The outer side of the closed end 41 a of the cylinder 41 isfixed to a tubular valve housing 49 having a closed end. The valvehousing 49 includes a valve chamber 48 that communicates to thedischarge valve port 44. The closed end of the valve housing 49 isprovided with a tubular air outlet passage 49 a that projects andcommunicates to the valve chamber 48. The air outlet passage 49 a isconnected to the air hose H2.

The discharge valve 45 includes a discharge valve member 54 and adiscoid rubber member 55. The discharge valve member 54 is integrallyformed by a disc 51, a tube 52 and the operation projection 53. The disc51 is shaped in conformance with an inner circumferential surface of thevalve chamber 48. The tube 52 axially extends from a rim of the disc 51(to right in FIG. 13) and guides the axial movement of the tube 52. Theoperation projection 53 projects from the center of the disc 51 to aninner side of the cylinder 41. The discoid rubber member 55 is fittedonto a basal portion of the operation projection 53. A dischargecommunication bore 51 a axially extends through a part of acircumferential portion of the disc 51. The discharge valve 45 ismovable in the forward-backward direction of the piston 42. Thedischarge valve 45 is capable of performing the closing operation in adirection in which the rubber member 55 closely contacts the dischargevalve port 44, that is, closes the discharge valve port 44. Thedischarge valve 45 is also capable of performing the opening operationin a direction in which the rubber member 55 is separated from thedischarge valve port 44, that is, opens the discharge valve port 44. Thedischarge valve 45 is urged to the inner side (left side in FIG. 13) ofthe cylinder 41 by a coil spring 56 supported on the closed end of thevalve housing 49. The spring coefficient of the coil spring 56 or thelike is set so that the discharge valve 45 will not perform the openingoperation only by compressed air, which will be described later.

As shown in FIG. 12, the piston 42 includes a discoid piston body 62,two rods 63, and a discoid disc 64. A seal ring 61 is fitted onto thecircumference of the piston body 62. The piston body 62 slides on theinner circumferential surface of the cylinder 41 with the seal ring 61located between. The rods 63 axially extend from outer circumferentialportions of the piston body 62. The disc 64 is flange-shaped and coupledto a distal end of each rod 63. Piston communication bores 65 axiallyextend through circumferential portions of the piston body 62. Thepiston communication bores 65 include inner openings (openings locatedtoward closed end 41 a of cylinder 41) defining the suction valve ports46. The piston communication bores 65 are arranged in locations (atangles) where the piston body 62 is free from the rods 63. The disc 64is also provided with communication portions 66 that communicate in theaxial direction.

The suction valve 47 of the present embodiment is an umbrella valve andformed by a discoid central support 47 a and an elastically deformedportion 47 b that extends radially outward from the central support 47a. The suction valve 47 is fixed to the piston body 62 on the centralsupport 47 a by the operation member 67 so that the elastically deformedportion 47 b covers the suction valve ports 46. More specifically, atubular large diameter portion 62 a axially projects from the center ofthe piston body 62. A tubular small diameter portion 62 b having a smalldiameter axially further projects from the center of the large diameterportion 62 a. The central support 47 a of the suction valve 47 is fittedonto the small diameter portion 62 b and located between the largediameter portion 62 a and the disc plate 68 in the axial direction.Additionally, the disc plate 68 is fixed by a head 67 a of the operationmember 67 that is thread-coupled or press-fitted in a central hole 62 cextending through the small diameter portion 62 b and the large diameterportion 62 a. This holds the central support 47 a (between the largediameter portion 62 a and the disc plate 68). The operation member 67opens the discharge valve 45 by pushing the operation projection 53 ofthe discharge valve 45 in accordance with the forward-backward movementof the piston 42 (refer to FIG. 13B).

As shown in FIG. 12, the piston 42 includes damper members 71 each ofwhich is integrally formed by a forward movement damper 71 a and abackward movement damper 71 b. The forward movement dampers 71 a contacta forward movement restriction 70 in a forward movement terminationposition. The backward movement dampers 71 b contact a backward movementrestriction 72 in a backward movement termination position. Morespecifically, a plurality of fixing holes 64 a is circumferentiallyarranged and axially extends through the disc 64 of the piston 42. Eachdamper member 71 includes a shaft 71 c received in a fixing hole 64 a,the forward movement damper 71 a located on one end of the shaft 71 c,and the backward movement damper 71 b located on the other end of theshaft 71 c. The forward movement damper 71 a and the backward movementdamper 71 b of the present embodiment are each semispherical and have aslightly larger diameter than the shaft 71 c. When the forward movementdamper 71 a is, for example, squeezed into the fixing hole 64 a, theshaft 71 c is fixed in the fixing hole 64 a. The forward movementrestriction 70 inwardly extends from the inner surface of the cylinder41 so as to contact the forward movement dampers 71 a on the forwardmovement termination position of the piston 42. An end housing 73, whichfunctions as a housing for the motor 43, is fixed to an opening of thecylinder 41 and closes the opening. The end housing 73 includes an endsurface defining the backward movement restriction 72, which contactsthe backward movement dampers 71 b on the backward movement terminationposition of the piston 42.

The disc 64 of the piston 42 includes a central portion provided with athreaded hole 64 b. The threaded hole 64 b engages with a threaded shaft74 that is rotated when driven by the motor 43. When the threaded shaft74 is rotated, the piston 42 having the rotation restriction is drivenforward and backward by the thread effect. More specifically, the motor43 includes a tubular yoke housing 75 having an closed end and the endhousing 73, which closes an opening (left end in FIG. 12) of the yokehousing 75. The motor 43 includes a magnet 76, which is fixed to aninner surface of the yoke housing 75, a rotation shaft 77, which isrotationally supported by an axial center of the yoke housing 75, and anarmature core 78 and a commutator 79 (with wound coils), which are fixedto the rotation shaft 77. The threaded shaft 74 is coupled to andintegrally rotational with the rotation shaft 77.

Communication bores 73 a axially extend through the end housing 73 ofthe motor 43. The communication bore 73 a communicates an inner side ofthe motor 43 and the space that receives the piston 42 in the cylinder41. Additionally, an external communication bore 73 b extends radially(in vertical direction in FIG. 12) through the end housing 73 andcommunicates the inner side of the motor 43 and an external space. Thus,the suction valve port 46, which the suction valve 47 is located on, isin communication with the exterior through the piston communicationbores 65, the communication portions 66, the communication bore 73 a,and the external communication bore 73 b.

As shown in FIG. 1A, the air pump AP and the washer pump WP, which areconfigured as described above, are electrically connected to acontroller 81 and driven by the controller 81.

The operation and effect of the controller 81 included in the on-vehicleoptical sensor cleaning system (on-vehicle optical sensor cleaningdevice) having the above configuration will now be described.

When the washer pump WP and the air pump AP are not driven, the nozzleunit 6 is in a state in which the nozzle member 9 is moved rearward tothe non-cleaning position by the urging force of the compression coilspring 27 (refer to FIG. 10). Thus, the nozzle member 9 is accommodatedin the nozzle receptacle 7 b of the on-vehicle optical sensor attachmentbracket 7 and does not project from the on-vehicle optical sensorattachment bracket 7. The ejection ports 8 (distal portion of nozzlemember 9) are located outside an image capturing range of the on-vehiclecamera 5. Therefore, if an image is captured when the cleaning is notperformed, the ejection ports 8 (distal portion of nozzle member 9) willnot interfere with the image capturing. Additionally, the nozzle unit 6including the nozzle member 9 is finely accommodated in the on-vehicleoptical sensor attachment bracket 7.

If a signal for starting the cleaning is received, for example, when aswitch SW (refer to FIG. 1A) located in the vehicle is operated or theshift lever SL of the gearshift device is operated to the reverseposition, the controller 81 controls the driving of the washer pump WP(pump motor) and the air pump AP (motor 43) to eject the fluid from theejection ports 8.

More specifically, the controller 81 controls the washer pump WP and theair pump AP as follows. The cleaning liquid is stored in the commonintake chamber D, which is located inside the nozzle member 9, to coverthe ejection ports 8. Then, air is fed to the nozzle member 9. Thisejects a gas-liquid mixture of the cleaning liquid and the air.Additionally, after the gas-liquid mixture is ejected, the controller 81controls the air pump AP to eject only air.

More specifically, as shown in FIG. 14, the controller 81 drives thewasher pump WP (pump motor) for predetermined period T1. This feeds thecleaning liquid to the cleaning liquid intake passage 32 c from thewasher pump WP through the cleaning liquid hose H1. Then, the cleaningliquid is supplied into the nozzle member 9 from the cleaning liquidintake passage 32 c through the cleaning-liquid-side check valve 33. Atthis time, the nozzle unit 6 is accommodated in the nozzle receptacle 7b and fixed by the on-vehicle optical sensor attachment bracket 7 sothat the ejection ports 8 are located below the common intake chamber Din the gravitational direction. Thus, the cleaning liquid supplied intothe nozzle member 9 is stored in the common intake chamber D and coversthe ejection ports 8 (cleaning liquid may be subtly leaked from theejection ports 8). In this case, the cleaning liquid also flows into thespace SP located proximate to the basal flange 25 b through a gap formeddue to the loose fitting of the tube 24 a and the inlet 31 d.

After stopping the washer pump WP (pump motor), the controller 81 drivesthe air pump AP (motor 43). More specifically, the controller 81 drivesthe motor 43 in the forward rotation (refer to period T2 in FIG. 14).This forwardly rotates the rotation shaft 77 and the threaded shaft 74and moves the piston 42 forward. The forward movement of the piston 42reduces the space (pump chamber P) in the cylinder 41 and compresses theair in the space (pump chamber P).

As shown in FIG. 13B, when the operation member 67 of the piston 42reaches and presses the operation projection 53, the discharge valve 45opens. The compressed high-pressure air is instantaneously dischargedfrom the air outlet passage 49 a through the discharge valve port 44 andthe discharge communication bore 51 a. Consequently, the air is fed tothe air intake passage 32 d of the nozzle unit 6 from the air pump APthrough the air hose H2 and then supplied into the nozzle member 9 fromthe air intake passage 32 d through the air-side check valve 34. The airis mixed with the cleaning liquid stored in the common intake chamber Dand ejected from the ejection ports 8 as the gas-liquid mixture. At thistime, the mainstream of the fluid (air) is linearly directed to thedistal end (ejection ports 8) of the nozzle member 9 by the inlet 31 d.Additionally, a side stream of the fluid (air) also flows into the spaceSP located proximate to the basal flange 25 b through the gap formed dueto the loose fitting between the tube 24 a and the inlet 31 d. Thefeeding pressure moves the nozzle member 9 frontward (refer to FIG. 11).Consequently, as shown in FIG. 1B, the ejection ports 8 of the nozzlemember 9 is moved to the cleaning position (refer to FIG. 11) from thenon-cleaning position (refer to FIG. 10) to approach an image capturingrange center X of the on-vehicle camera 5. The image capturing range ofthe present embodiment is a range of an image captured by the on-vehiclecamera 5 (image capturing element) through the lens 5 b, that is, arange shown on a display DSP. FIG. 1B shows the view shown on thedisplay DSP and an ejection port 8 (distal portion of nozzle member 9)located in the image capturing range. Also, FIG. 1B schematically showsan ejection port 8 (distal portion of nozzle member 9) located at thenon-cleaning position outside the image capturing range indicated bydouble-dashed lines. At this time, the stored cleaning liquid covers theejection ports 8. This further increases the pressure of the drawn airin an instantaneous manner. The cleaning liquid is mixed with the air aspushed by the high pressure and ejected from the ejection ports 8. Thus,the lens 5 b is cleaned by the gas-liquid mixture ejected under higherpressure in a satisfactory manner.

Then, the controller 81 drives the motor 43 in the reverse rotation(refer to T3 in FIG. 14). This reversely rotates the threaded shaft 74with the rotation shaft 77 and moves the piston 42 backward. Thebackward movement enlarges the space (pump chamber P) between the piston42 and the cylinder 41 and results in the space (pump chamber P) havingnegative pressure. This opens the suction valve 47 and draws air intothe cylinder 41 (pump chamber P) from the suction valve ports 46. Morespecifically, the air is drawn into the cylinder 41 (pump chamber P)from the outside of the air pump AP through the external communicationbore 73 b and the communication bore 73 a of the motor 43, thecommunication portions 66, and the piston communication bores 65(suction valve ports 46). At this time, the operation member 67 of thepiston 42 is separated from the operation projection 53 of the dischargevalve 45. Thus, the discharge valve 45 performs the closing operation toclose the discharge valve port 44.

Then, the controller 81 drives the motor 43 of the air pump AP in theforward rotation (refer to period T4 in FIG. 14) as described abovewithout driving the washer pump WP (pump motor) so that only air isejected. This feeds air from the air pump AP to the air intake passage32 d through the air hose H2 and then supplied into the nozzle member 9from the air intake passage 32 d through the air-side check valve 34.Consequently, when the nozzle member 9 moves frontward (to the cleaningposition), the ejection ports 8 eject only the air. As a result, thecleaning liquid, which was applied to the lens 5 b when the gas-liquidmixture was ejected, is blown away by the ejection of only air.

The controller 81 drives the motor 43 of the air pump AP in the reverserotation as described above (refer to period T5 in FIG. 14) andterminates the control with air drawn in the cylinder 41 (pump chamberP).

The first embodiment has the advantages described below.

(1) The controller 81 controls the washer pump WP and the air pump AP.The cleaning liquid is stored in the nozzle member 9 (common intakechamber D) to cover the ejection ports 8. Then, air is fed to the nozzlemember 9. This ejects the gas-liquid mixture of the cleaning liquid andthe air. In this configuration, when the air is fed into the nozzlemember 9, the cleaning liquid is stored and covers the ejection ports 8.Thus, the air pressure is further increased in an instantaneous manner.The cleaning liquid is mixed with the air as pushed by the high pressureand ejected from the ejection ports 8. Thus, the gas-liquid mixture isejected under higher pressure. This effectively cleans the lens 5 b.

(2) The controller 81 controls the air pump AP to eject only air afterejecting the gas-liquid mixture. The ejection of only air blows away thecleaning liquid, which was applied to the lens 5 b when the gas-liquidmixture was ejected. This allows the display DSP to show a capturedimage having limited deformation caused by the cleaning liquid.

(3) The nozzle member 9 is capable of moving frontward and rearwardwhile accommodated in the cylinder housing 21. Additionally, the nozzlemember 9 includes a distal portion provided with the ejection ports 8and is urged and moved frontward by air feeding pressure. Thus, thedistal portion will not project when air is not fed. This improves theornamental feature when the cleaning is not performed. Additionally,when the cleaning is not performed, the nozzle member 9 is located atthe non-cleaning position outside the image capturing range of theon-vehicle camera 5 and does not interfere with the image capturing.When the cleaning is performed, the nozzle member 9 moves to thecleaning position located close to the image capturing range center X ofthe on-vehicle camera 5 and ejects the fluid from a position close tothe front surface of the lens 5 b. This effectively cleans the lens 5 b.

(4) After stopping the washer pump WP (pump motor), the controller 81drives the air pump AP (motor 43) to eject the gas-liquid mixture. Thus,the air is assuredly fed after the cleaning liquid is stored. Thisensures the ejection of the gas-liquid mixture under higher pressure.

(5) The feeding pressure of the fluid (air) moves the nozzle member 9frontward. The fluid is ejected from the ejection ports 8, which arelocated in the distal portion of the nozzle member 9, toward the lens 5b. The gas-liquid mixture of the cleaning liquid and the air may beejected, for example, by feeding the cleaning liquid and then air to thecommon intake chamber D. This removes an object from the lens 5 b.Further, only air may be ejected by feeding only air to the commonintake chamber D. This blows away the cleaning liquid from the lens 5 b.Additionally, when the cleaning liquid is fed to the common intakechamber D, the air-side check valve 34 prevents a reverse flow of thecleaning liquid toward the air intake passage 32 d. Also, when the airis fed to the common intake chamber D, the cleaning-liquid-side checkvalve 33 prevents a reverse flow of the air toward the cleaning liquidintake passage 32 c. This selectively ejects the gas-liquid mixture andthe air in an appropriate manner.

(6) The inlet member 31 includes the tubular inlet 31 d thatcommunicates the downstream side of the cleaning-liquid-side check valve33 and the downstream side of the air-side check valve 34 and is looselyfitted to the inner circumferential surface of the nozzle member 9 fromthe basal end of the nozzle member 9. This linearly directs themainstream of the fluid to the distal end (ejection ports 8) of thenozzle member 9. Additionally, the side stream of the fluid also flowsto the side of the basal flange 25 b (space SP) through the gap formeddue to the loosely fitting. The feeding pressure moves the nozzle member9 frontward. In this configuration, some of the cleaning liquid mayremain in the space SP between the basal flange 25 b and the basal endof the cylinder housing 21. Even in this case, when ejecting only air,air may be almost exclusively ejected without including the remainedcleaning liquid because the mainstream passage in the inlet 31 d and thespace SP are separated by the inlet 31 d. This prevents a mixture of thecleaning liquid when only air is to be ejected. Thus, the lens 5 b maybe free from the cleaning liquid, for example, by blowing away thecleaning liquid from the lens 5 b with the air that is ejected almostexclusively.

(7) The piston unit 28 is formed by a subassembly in which the pistonnozzle member 24, the flange member 25, the spring holder 23, and thecompression coil spring 27 are coupled. The piston unit 28 is coupled byinserting into the cylinder housing 21 from the basal end of thecylinder housing 21. This improves the coupling efficiency, for example,as compared to a coupling configuration in which the piston nozzlemember 24 is inserted into the cylinder housing 21 from the distal endof the cylinder housing 21 and other members including the flange member25 are each inserted into the cylinder housing 21 from the basal end ofthe cylinder housing 21.

(8) The separation restriction grooves 25 d axially extend in thepacking fitting recess 25 c that outwardly opens in the radial directionof the basal flange 25 b. The fitting portion 26 a of the lip packing26, which is fitted to the packing fitting recess 25 c, includes theseparation restriction projections 26 e. The separation restrictionprojections 26 e are fitted to the separation restriction grooves 25 d.This limits situations in which the lip packing 26 is removed from thebasal flange 25 b.

(9) The sensor receptacle 7 a, which accommodates the on-vehicle camera5, and the nozzle receptacle 7 b, which accommodates the nozzle unit 6,are integrally formed with each other. Thus, the on-vehicle camera 5 andthe nozzle unit 6 may be coupled to the vehicle 1 while obtaining thefavorable ornamental feature.

(10) The on-vehicle optical sensor attachment bracket 7 includes theliquid release portions 7 j, 7 k capable of receiving the cleaningliquid at locations corresponding to the ejection ports 8 of the nozzlemember 9 when located at the non-cleaning position. This limits aleakage of the cleaning liquid to the exterior even when, for example,the cleaning liquid is subtly leaked from the ejection ports 8 of thenozzle member 9 located at the non-cleaning position. Thus, situationsare limited in which the cleaning liquid is leaked form the ejectionports 8 and applied to the lens 5 b of the on-vehicle camera 5. Theliquid release portions 7 j, 7 k of the present embodiment are formed inthe sensor receptacle 7 a and the nozzle receptacle 7 b by communicatingthe sensor receptacle 7 a and the nozzle receptacle 7 b, that is, apartition wall is not formed, at locations corresponding to the ejectionports 8. This facilitates the receiving of the cleaning liquid, that is,hinders the leakage of the cleaning liquid toward the lens 5 b, ascompared to a structure in which a liquid release portion is located onone side.

(11) The liquid release portion 7 j is provided with the discharge bores7 m, 7 n that open in directions different from the exposure bore 7 f(lens 5 b). In the present embodiment, the discharge bores 7 m, 7 n areopened in the gravitational direction (downward). The cleaning liquidleaked to (received in) the liquid release portion 7 j from the ejectionports 8 is discharged from the discharge bores 7 m, 7 n. This prevents,for example, a leakage of the cleaning liquid toward the lens 5 b.

(12) The nozzle receptacle 7 b includes the rotation restricting portion16 that engages with the rotation restricted portion 15 arranged on theouter circumferential surface of the cylinder housing 21 of the nozzleunit 6. Thus, the cylinder housing 21 is easily positioned. Thisaccurately directs the ejection ports 8 of the nozzle member 9, that is,the fluid ejection, toward the lens 5 b.

(13) The on-vehicle optical sensor unit 3 is fixed to a position locatedslightly toward the driver seat side (right side) from the lateralcenter line C of the vehicle 1. Thus, the sensor receptacle 7 a and theon-vehicle camera 5 are located toward one side (driver seat side) fromthe lateral center line C of the vehicle 1. Additionally, the nozzlereceptacle 7 b and the nozzle member 9 are located further toward theside relative to the on-vehicle camera 5. Thus, the cleaning liquid,which is the fluid ejected from the ejection ports 8 toward the lens 5b, is ejected toward the lateral center line C of the vehicle 1. Thislimits situations in which the cleaning liquid is dispersed to alaterally outer side of the vehicle 1.

(14) The suction valve ports 46 are openings of the piston communicationbores 65 formed in the piston 42. The suction valve ports 46 are incommunication with the exterior through the piston communication bores65 and the external communication bore 73 b located in the end housing73 of the motor 43. This increases the distance between the externalcommunication bore 73 b and the suction valve ports 46 and reduces anexternal leakage of noise such as a whistle sound generated in thesuction valve ports 46 and a flapping sound of the suction valve 47 whenthe piston 42 moves backward.

(15) The operation member 67 is fastened to the piston 42 and performsthe opening operation by pushing the discharge valve 45 when the piston42 moves forward. The suction valve 47 is fastened to the piston 42 bythe operation member 67. Thus, the operation member 67 for pushing thedischarge valve 45 also functions to fasten the suction valve 47.

(16) The piston 42 includes the damper members 71. Each damper member 71is integrally formed by a forward movement damper 71 a, which contactsthe forward movement restriction 70 in the forward movement terminationposition, and a backward movement damper 71 b, which contacts thebackward movement restriction 72 in the backward movement terminationposition. Thus, shocks on the forward movement termination position andthe backward movement termination position may be absorbed whilereducing the number of components as compared to a structure in which aforward movement damper and a backward movement damper are separatebodies.

The first embodiment may be modified as follows.

As shown in FIG. 15, an orifice piece 82 may be located on a downstreamposition between the cleaning-liquid-side check valve 33 and theair-side check valve 34 of the first embodiment. The orifice piece 82decreases the cross-sectional area of the cleaning-liquid-side flowpassage to be smaller than the cross-sectional area of the air-side flowpassage. In this structure, for example, the flow rate of the cleaningliquid fed to the common intake chamber D is easily controlled.Additionally, the cross-sectional area of the air flow passage isensured without any decrease. This maintains the feeding pressure ofair. The cleaning liquid may remain in space located at an immediatelydownward position of the cleaning-liquid-side check valve 33. Even insuch a case, when ejecting only air, air may be almost exclusivelyejected without including the remained cleaning liquid because theorifice piece 82 separates the air flow passage and the space. Thislimits a mixture of the cleaning liquid when only air is to be ejected.Thus, the lens 5 b may be free from the cleaning liquid, for example, byblowing away the cleaning liquid from the lens 5 b with the air that isejected almost exclusively.

The first embodiment may be modified as shown in FIG. 16. In thisexample, the inlet member 31 (refer to FIG. 10) of the first embodimentis changed to an inlet communication member 91 that includes a cleaningliquid inlet 91 a and an air communication passage 91 b. The cleaningliquid inlet 91 a is in communication with the downstream side of thecleaning liquid intake passage 32 c. The cleaning liquid inlet 91 a istubular and loosely fitted to the inner circumferential surface of thenozzle member 9 from the basal end of the nozzle member 9. The aircommunication passage 91 b communicates the space SP located between thebasal flange 25 b and the basal end of the cylinder housing 21 to thedownstream side of the air intake passage 32 d. In this example (FIG.16), same reference characters are given to components that are the sameas the corresponding components of the first embodiment (refer to FIG.10).

The cleaning-liquid-side check valve 92 is located on the distal portionof the cleaning liquid inlet 91 a. More specifically, a distal tube 91 chaving a closed end with a decreased diameter extends from the distalportion of the cleaning liquid inlet 91 a. A through hole 91 d extendsradially outward through the distal tube 91 c from an inner side of thedistal tube 91 c. The closed end of the distal tube 91 c is providedwith a valve fixing hole 91 e that extends parallel to the through hole91 d. The cleaning-liquid-side check valve 92 is fixed to the valvefixing hole 91 e. The cleaning-liquid-side check valve 92, which is anumbrella valve, includes a support shaft 92 a and an elasticallydeformed portion 92 b that extends radially outward from one end of thesupport shaft 92 a. The support shaft 92 a is inserted and fixed in thevalve fixing hole 91 e so that the elastically deformed portion 92 bcovers the through hole 91 d. Thus, the cleaning-liquid-side check valve92 allows the cleaning liquid to flow from the cleaning liquid inlet 91a to the common intake chamber D, which is located at the distal end ofthe cleaning liquid inlet 91 a, and blocks a fluid flowing into thecleaning liquid inlet 91 a from the common intake chamber D. Thecleaning-liquid-side check valve 92 is located on the small diameterpart of the distal portion of the cleaning liquid inlet 91 a. Thus, astep formed by the large diameter part and the small diameter partavoids a situation in which the cleaning-liquid-side check valve 92interferes with the backward and forward movement of the nozzle member9.

The air-side check valve 93 is located between a radially inner side ofthe nozzle member 9 and the cleaning liquid inlet 91 a. Morespecifically, the basal portion of the nozzle member 9 includes a valvereceptacle 94 that opens radially inward. The valve receptacle 94 holdsthe air-side check valve 93. The air-side check valve 93 is formed by arubber material and includes a support tube 93 a, which is fitted intoand fixed to the valve receptacle 94, and a valve portion 93 b, whichprojects radially inward from a basal portion of the support tube 93 aand obliquely extends toward the distal side. The valve portion 93 b isin press contact with the outer circumferential surface of the cleaningliquid inlet 91 a. The valve portion 93 b allows air to flow to thecommon intake chamber D from the space SP located at the basal end ofthe cylinder housing 21 and blocks a fluid flowing to the space SP fromthe common intake chamber D. In this structure, the cleaning-liquid-sidecheck valve 92 and the air-side check valve 93 are arranged next to eachother in the longitudinal direction of the cylinder housing 21(frontward-rearward movement direction of nozzle member 9, longitudinaldirection of nozzle member 9).

In this structure, the cleaning liquid is fed to the common intakechamber D, which is a small space located at the distal end of thecleaning liquid inlet 91 a. The air-side check valve 93 is located atthe radially inner side of the nozzle member 9 (between nozzle member 9and cleaning liquid inlet 91 a). This prevents the cleaning liquid fromentering the space SP located at the basal end of the cylinder housing21. Additionally, the air communication passage 91 b communicates thespace SP and the downstream side of the air intake passage 32 d. Thus,the nozzle member 9 is moved frontward by the feeding pressure of theair, and also the air is fed to the common intake chamber D from thespace SP through the air-side check valve 93 and the gap formed due tothe loosely fitting. In this structure, the common intake chamber D is asmall space located at the distal end of the cleaning liquid inlet 91 a,and air is fed through the gap formed due to the loosely fitting andlocated outside the cleaning liquid inlet 91 a. Thus, even when thecleaning liquid is fed to the common intake chamber D and then air isfed to eject the gas-liquid mixture, the cleaning liquid is almostcompletely removed from air flow passages including the common intakechamber D. This limits a mixture of the cleaning liquid when only air isto be ejected. Thus, the lens 5 b may be free from the cleaning liquid,for example, by blowing away the cleaning liquid from the lens 5 b withthe air that is ejected almost exclusively. Additionally, thecleaning-liquid-side check valve 92 and the air-side check valve 93 arearranged next to each other in the longitudinal direction of thecylinder housing 21. This may reduce the size in a direction orthogonalto the longitudinal direction, for example, compared to a structurehaving a longitudinal arrangement. In the same manner as the firstembodiment, in this example (refer to FIG. 16), the cleaning liquidintake passage 32 c and the air intake passage 32 d are arranged next toeach other in the direction orthogonal to the longitudinal direction.However, a cleaning liquid intake passage and an air intake passage maybe arranged, for example, in the longitudinal direction. This may reducethe size in the direction orthogonal to the longitudinal direction.

In the first embodiment, the inlet member 31 includes the tubular inlet31 d that communicates the downstream side of the cleaning-liquid-sidecheck valve 33 and the downstream side of the air-side check valve 34and is loosely fitted to the inner circumferential surface of the nozzlemember 9 from the basal end of the nozzle member 9. However, the inlet31 d (inlet member 31) may be omitted from the structure.

In the first embodiment, the piston unit 28 is formed by a subassemblyin which the piston nozzle member 24, the flange member 25, the springholder 23, and the compression coil spring 27 are coupled. The pistonunit 28 is configured to be coupled to the cylinder housing 21 by beinginserted into the cylinder housing 21 from the basal end of the cylinderhousing 21. However, the piston unit 28 may be configured not to becoupled in such a manner. For example, as shown in FIG. 16, the springholder 23 of the first embodiment may be omitted. In this case, thecoupling structure may be such that the piston nozzle member 24 isinserted into the cylinder housing 21 from the distal end of thecylinder housing 21 whereas the compression coil spring 27 and theflange member 25 are inserted into the cylinder housing 21 from thebasal end of the cylinder housing 21.

In the first embodiment, the separation restriction grooves 25 d axiallyextend in the packing fitting recess 25 c, and the separationrestriction projections 26 e, which are fitted to the separationrestriction grooves 25 d, project from the fitting portion 26 a of thelip packing 26. However, the separation restriction grooves 25 d and theseparation restriction projections 26 e may be omitted.

In the first embodiment, the on-vehicle optical sensor attachmentbracket 7 includes the liquid release portions 7 j, 7 k, which arecapable of receiving the cleaning liquid, at locations corresponding tothe ejection ports 8 of the nozzle member 9 when located at thenon-cleaning position. However, the liquid release portions 7 j, 7 k maybe omitted from the structure. Additionally, in the first embodiment,the liquid release portions 7 j, 7 k are formed in the sensor receptacle7 a and the nozzle receptacle 7 b. However, only one of the liquidrelease portions 7 j, 7 k may be formed.

In the first embodiment, the liquid release portions 7 j, 7 k areprovided with the discharge bores 7 m, 7 n that open in directionsdifferent from the exposure bore 7 f (lens 5 b). In the firstembodiment, the discharge bores 7 m, 7 n are open in the gravitationaldirection (downward). However, the discharge bores 7 m, 7 n may beomitted from the structure. Alternatively, the structure may includeonly one of the discharge bore 7 m of the sensor receptacle 7 a and thedischarge bores 7 n of the nozzle receptacle 7 b. This structure alsolimits an external leakage of the cleaning liquid when the amount of thecleaning liquid is small. This limits application of the cleaning liquidto the lens 5 b of the on-vehicle camera 5.

In the first embodiment, the nozzle receptacle 7 b includes the rotationrestricting portion 16 that engages with the rotation restricted portion15 arranged on the outer circumferential surface of the cylinder housing21 of the nozzle unit 6. Instead, another configuration or process maybe used to position the cylinder housing 21.

In the first embodiment, the sensor receptacle 7 a and the on-vehiclecamera 5 are located toward one side (driver seat side) from the lateralcenter line C of the vehicle 1. Additionally, the nozzle receptacle 7 band the nozzle member 9 are located further toward the side relative tothe on-vehicle camera 5. However, the components may be located at otherpositions. For example, when the sensor receptacle 7 a and theon-vehicle camera 5 are located toward one side from the lateral centerline C of the vehicle 1, the nozzle receptacle 7 b and the nozzle member9 may be located toward the other side relative to the on-vehicle camera5. Alternatively, the sensor receptacle 7 a and the on-vehicle camera 5may be located on the lateral center line C of the vehicle 1.

In the first embodiment, the suction valve ports 46 are in communicationwith the exterior through the external communication bore 73 b locatedin the end housing 73. Instead, an external communication bore may belocated in another housing of the motor 43. The yoke housing 75 may beprovided with an external communication bore through which the suctionvalve ports 46 are in communication with the exterior.

In the first embodiment, the operation member 67 for pushing thedischarge valve 45 also functions to fasten the suction valve 47.Instead, the functions may have independent structures.

In the first embodiment, the air pump AP is used as a portion of theon-vehicle optical sensor cleaning system. However, the air pump may beused for another system.

In the first embodiment, the controller 81 controls the air pump AP toeject only air after ejecting the gas-liquid mixture. Instead, thecontrol may be terminated when the gas-liquid mixture is ejected withoutthe ejection of only air. Additionally, for example, when a liquid suchas raindrops is applied to the lens 5 b, only air may be ejected withoutthe ejection of the gas-liquid mixture.

In the first embodiment, the nozzle member 9 is capable of movingfrontward and rearward while accommodated in the cylinder housing 21.Additionally, the nozzle member 9 includes a distal portion providedwith the ejection ports 8 and is urged and moved frontward by feedingpressure of a fluid (air). Instead, the nozzle member 9 may be changedto an immovable nozzle member that is arranged in the vehicle 1 and doesnot move frontward and rearward.

In the first embodiment, the controller 81 starts to drive the air pumpAP (motor 43) so that the gas-liquid mixture is ejected after stoppingthe washer pump WP (pump motor). However, the configuration may bechanged to another control as long as the cleaning liquid is stored inthe nozzle member 9 (common intake chamber D) to cover the ejectionports 8, and then air is fed to the nozzle member 9.

For example, before the washer pump WP (pump motor) is stopped, thedriving of the air pump AP (motor 43) may be started. More specifically,the control may be performed so that, for example, the driving of thewasher pump WP (pump motor) and the air pump AP (motor 43) aresimultaneously started. Then, after the washer pump WP (pump motor) isstopped, the operation member 67 of the air pump AP may push theoperation projection 53 of the discharge valve 45 to open the dischargevalve 45. This shortens the time until the gas-liquid mixture isejected.

In the first embodiment, when the piston 42 moves forward, the operationmember 67 pushes the operation projection 53 of the discharge valve 45to open the discharge valve 45. Instead, the discharge valve 45 may openusing air compressed by the forward movement of the piston 42. Thus, theoperation projection 53 may be omitted.

In the first embodiment, the on-vehicle optical sensor unit 3 isarranged on the rear door 2. However, the on-vehicle optical sensor unit3 may be arranged on any position of a rear portion of the vehicle 1.Further, the on-vehicle optical sensor unit 3 may be arranged on a frontportion or a side portion (near door mirror) of the vehicle 1.

A second embodiment of the vehicle will now be described with referenceto FIGS. 17A to 25.

As shown in FIG. 17A, the rear door 2 is located on the rear of thevehicle 1, and an on-vehicle optical sensor unit 103 is arranged on therear door 2. The on-vehicle optical sensor unit 103 of the secondembodiment is fixed to a position located slightly toward the driverseat side (right side) from the lateral center line C of the vehicle 1.

As shown in FIGS. 18 to 20, the on-vehicle optical sensor unit 103includes an on-vehicle camera 105, which functions as an on-vehicleoptical sensor, a nozzle unit 106, which functions as an on-vehicleoptical sensor cleaning device, and an on-vehicle optical sensorattachment bracket 107.

The on-vehicle camera 105 includes a cuboid body 105 a, whichaccommodates an image capturing element (not shown), and a lens 105 b,which is located on one surface of the body 105 a and functions as asensing surface (external image capturing surface). The lens 105 bincludes a central major portion defining an effective surface 105 cthat is a range of the surface of the lens 105 b corresponding to theimage capturing range W (refer to FIG. 25) of the image capturingelement.

As shown in FIGS. 17A, 17B, for example, when the shift lever SL of thegearshift device is operated to the reverse position, the on-vehiclecamera 105 transmits a captured image of a rear side of the vehicle 1 tothe in-vehicle display DSP to show the image. The on-vehicle camera 105is fixed to the rear door 2 by the on-vehicle optical sensor attachmentbracket 107 so that the lens 105 b (effective surface 105 c) facesobliquely downward to capture an oblique downward image of the rear sideof the vehicle 1.

As shown in FIGS. 18 and 19, the on-vehicle optical sensor attachmentbracket 107 is integrally formed by a sensor fastening portion 107 a,which fastens the on-vehicle camera 105, a nozzle receptacle 107 b,which accommodates the nozzle unit 106, and a vehicle fastening portion107 c.

As shown in FIGS. 20, 21, and 25, the entire contour of the nozzle unit106 is cylindrical. The nozzle unit 106 includes a movable nozzle member109 including ejection ports 108. When moved (movable) from thenon-cleaning position (refer to FIGS. 18, 20 and 21) to the cleaningposition (refer to FIGS. 19 and 25), the nozzle member 109 projectsoutward and ejects a fluid from the ejection ports 108 toward the lens105 b. In the present embodiment, the fluid is one of a cleaning liquid,air, and a gas-liquid mixture.

More specifically, as shown in FIG. 21, the nozzle unit 106 includes anelongated tubular cylinder housing 121, the nozzle member 109, an inletmember 122, and an intake member 123.

As shown in FIG. 20, the cylinder housing 121 has the form of anelongated tube and includes an outer circumference. The cylinder housing121 is held when the outer circumference is accommodated in the nozzlereceptacle 107 b of the on-vehicle optical sensor attachment bracket107.

As shown in FIG. 21, the nozzle member 109 includes an elongated tubularpiston member 124, a distal nozzle member 125 fixed to a distal portionof the piston member 124, and a nozzle tip 126 fixed to the distalnozzle member 125.

A basal flange 124 a projects radially outward from a basal portion ofthe piston member 124. A lip packing 127 is fitted to the piston member124 at a location further in the basal direction from the basal flange124 a. When the piston member 124 is capable of moving frontward andrearward in the cylinder housing 121, the lip packing 127 slides whilepress-contacting an inner circumferential surface of the cylinderhousing 121. The distal nozzle member 125 includes an inner fitting tube125 a, which is fitted into the distal portion of the piston member 124,and a bent tip receptacle 125 b, which is in communication with a distalportion of the inner fitting tube 125 a.

As shown in FIG. 22, the nozzle tip 126 is a block that may be fitted tothe tip receptacle 125 b. As shown in FIGS. 21 and 25, when fitted tothe tip receptacle 125 b, the nozzle tip 126 forms the ejection ports 8together with a portion of the inner surface of the tip receptacle 125b. This also determines an ejection direction (ejection axis F (refer toFIG. 25)) and an ejection pattern of the fluid. The ejection axis F ofthe second embodiment is inclined inward from a direction orthogonal tothe frontward-rearward movement direction (in FIG. 25,frontward-rearward movement axis L1) of the nozzle member 109, that is,in a direction in which the nozzle member 109 becomes closer to thecenter of the lens 105 b when moved frontward. Additionally, in thesecond embodiment, the ejection axis F refers to the center line of thefluid ejected from the ejection ports 108. In the second embodiment, thepiston member 124 (ejection ports 108) includes an inner space definingthe common intake chamber D that is capable of drawing in a cleaningliquid and air.

As shown in FIG. 21, the distal nozzle member 125 (tip receptacle 125 b)includes a distal surface to which a cover 128 is fixed.

The inlet member 122 includes a tubular outer fitting portion 122 a,which is fitted onto a basal portion of the cylinder housing 121, a tube122 b, which has a diameter that decreases as extending from a basal endof the outer fitting portion 122 a in the axial direction (toward thebasal side), an inner extension 122 c, which extends radially inwardfrom the basal end of the outer fitting portion 122 a, and a tubularinlet 122 d, which extends from the inner extension 122 c in thecylinder housing 121 (toward the distal side in axial direction). Thecylinder housing 121 is provided with space SP formed between the innerextension 122 c and the basal flange 124 a (lip packing 127). In thenozzle member 109, the basal flange 124 a is urged toward the basalside, that is, the inner extension 122 c, of the cylinder housing 121 bya compression coil spring 129 including one end supported by the distalportion of the cylinder housing 121. The outer diameter of the inlet 122d is set slightly smaller than the inner diameter of the piston member124 so that the inlet 122 d is loosely fitted to the innercircumferential surface of the piston member 124 from the basal end ofthe nozzle member 109.

As shown in FIGS. 18, 21, and 23, the intake member 123 includes firstto third intake members 131 to 133. The first intake member 131 includesan outer fitting portion 131 a, which is fitted onto the tube 122 b ofthe inlet member 122, and a circular rod 131 b, which covers the basalportion of the tube 122 b. As shown in FIG. 21, a first cleaning liquidflow passage 131 c extends through a circumferential portion of the rod131 b located radially outward in the axial direction(frontward-rearward movement axis L1). Additionally, the rod 131 bincludes a radially inward portion provided with an annular air flowpassage 131 d that opens toward the distal side (inlet member 122). Asshown in FIG. 23, a tubular air intake passage 131 e projects from acircumferential portion of the rod 131 b radially outward and includesan interior that is in communication with the air flow passage 131 d.Additionally, an air-side check valve 134 is located proximate to anopen end of the air flow passage 131 d between the air intake passage131 e and the common intake chamber D (inside the piston member 124).The air-side check valve 134, which is an umbrella valve, includes asupport shaft 134 a and an elastically deformed portion 134 b thatextends radially outward from one end of the support shaft 134 a. Thesupport shaft 134 a is inserted and fixed to an axial center hole 131 fformed in the rod 131 b so that the elastically deformed portion 134 bcovers the opening of the air flow passage 131 d. Thus, the air-sidecheck valve 134 allows air to flow to the common intake chamber D fromthe air intake passage 131 e (air flow passage 131 d) and blocks a fluidflowing to the air intake passage 131 e (air flow passage 131 d) fromthe common intake chamber D.

The second intake member 132 includes an inner fitting portion 132 a,which is fitted into and fixed to a basal portion of the first intakemember 131, and a valve reception tube 132 b, which extends and has aslightly smaller diameter than the rod 131 b. Additionally, a secondcleaning liquid flow passage 132 c axially extends from the interior ofthe valve reception tube 132 b through a circumferential portion of thesecond intake member 132 and communicates to the first cleaning liquidflow passage 131 c. As shown in FIG. 23, the third intake member 133includes an inner fitting portion 133 a, which is fitted into and fixedto the basal opening of the valve reception tube 132 b, and a tubularcleaning liquid intake passage 133 b, which communicates with and bendsfrom an inner side of the inner fitting portion 133 a located in thevalve reception tube 132 b and projects radially outward (in presentembodiment, same direction as air intake passage 131 e). The valvereception tube 132 b accommodates a cleaning-liquid-side check valve 135between the cleaning liquid intake passage 133 b and the common intakechamber D (second cleaning liquid flow passage 132 c). Thecleaning-liquid-side check valve 135, which is a spring-type checkvalve, includes a valve member 136 and a valve spring 137 that urges thevalve member 136. The valve member 136 of the second embodiment isformed by a resin member 136 a and a rubber member 136 b. The rubbermember 136 b is urged toward an open end of the third intake member 133by urging force of the valve spring 137. Thus, the cleaning-liquid-sidecheck valve 135 allows the cleaning liquid to flow to the common intakechamber D (first and second cleaning liquid flow passages 131 c, 132 c)from the cleaning liquid intake passage 133 b and blocks a fluid flowingto the cleaning liquid intake passage 133 b from the common intakechamber D. In the structure of the second embodiment, thecleaning-liquid-side check valve 135 and the air-side check valve 134are arranged next to each other in the longitudinal direction of thecylinder housing 21 (frontward-rearward movement direction of nozzlemember 109).

As shown in FIG. 17A, the cleaning liquid intake passage 133 b isconnected to the washer pump WP by the cleaning liquid hose H1, and theair intake passage 131 e is connected to the air pump AP by the air hoseH2.

The washer pump WP is capable of feeding the cleaning liquid, which is afluid stored in the tank T. When the internal pump motor (not shown) isdriven, the cleaning liquid is fed to (drawn in) the cleaning liquidintake passage 133 b through the cleaning liquid hose H1.

The air pump AP is capable of instantaneously discharging compressedhigh-pressure air. When driven, air is fed to (drawn in) the nozzle unit6 (more specifically, air intake passage 32 d) through the air hose H2.

As shown in FIG. 17A, the air pump AP and the washer pump WP, which areconfigured as described above, are electrically connected to thecontroller 81 and driven by the controller 81.

As shown in FIG. 25, in the second embodiment, the nozzle member 109 isarranged to be movable so that the ejection axis F of the fluid ejectedfrom the ejection ports 108 traverses (passes) a dividing center Y(e.g., refer to FIGS. 18 and 19) that divides the lens 105 b (effectivesurface 105 c) into two. More specifically, the dividing center Yintersects with an image capturing range center line X1 and extendsthrough the peak of the lens 105 b. The dividing center Y divides thesurface of the lens 105 b into two, that is, a region close to thenozzle member 109 and a region distant from the nozzle member 109.

More specifically, the nozzle member 109 of the second embodiment isarranged to be capable of moving frontward and rearward in a directioninclined relative to the image capturing range center line X1 so thatthe ejection ports 108 approach the image capturing range center line X1of the on-vehicle camera 105 when moved frontward. In other words, thefrontward-rearward movement axis L1 of the nozzle member 109 is set tobe inclined relative to the image capturing range center line X1 of theon-vehicle camera 105. The nozzle member 109 is arranged to be movableso that the ejection axis F traverses an effective range Z1 (rangecorresponding to image capturing range W) that extends from one end tothe other end of the effective surface 105 c and further a lens range Z2that extends from one end to the other end of the lens 105 b. The nozzlemember 109 is set to become incapable of moving (frontward) and stopwhen the ejection axis F traverses the lens range Z2, which extends fromone end to a further end of the lens 105 b, and reaches the further end(left end in FIG. 25) of the lens 105 b.

Additionally, the nozzle member 109 is set so that a cleaning angle θformed by the ejection axis F and a tangent line S of the lens 105 bwhere the cleaning liquid hits is 22° or greater. More specifically,when the ejection axis F reaches the further end of the lens 105 b(refer to FIG. 25), the cleaning angle θ is set to be 22° or greater and32° in the second embodiment. The value of the cleaning angle θ being22° or greater is obtained through experimental results. In theexperiment, the lens 105 b was cleaned in a satisfactory manner (inwhich smudge was removed almost completely) when the cleaning angle θwas 22° or greater.

The operation and effect of the controller 81 of the on-vehicle opticalsensor cleaning system (on-vehicle optical sensor cleaning device)having the above configuration will now be described.

When the washer pump WP and the air pump AP are not driven, the nozzlemember 109 is moved rearward to the non-cleaning position by the urgingforce of the compression coil spring 129 (refer to FIGS. 18, 20, and23). Thus, the nozzle member 109 (ejection ports 108) is located outsidethe image capturing range of the on-vehicle camera 105 (refer todouble-dashed line in FIG. 17B). Therefore, if an image is captured whenthe cleaning is not performed, the ejection ports 108 (distal portion ofnozzle member 109) will not interfere with the image capturing.

If a signal for starting the cleaning is received, for example, when theswitch SW (refer to FIG. 17A) located in the vehicle is operated or theshift lever SL of the gearshift device is operated to the reverseposition, the controller 81 controls the driving of the washer pump WP(pump motor) and the air pump AP (motor 43) so that the fluid is ejectedfrom the ejection ports 108.

More specifically, the controller 81 controls the washer pump WP and theair pump AP as follows. The cleaning liquid is stored in the commonintake chamber D, which is located inside the nozzle member 109, tocover the ejection ports 108. Then, air is fed to the nozzle member 109.This ejects a gas-liquid mixture of the cleaning liquid and the air.Additionally, after the gas-liquid mixture is ejected, the controller 81controls the air pump AP to eject only air.

More specifically, the controller 81 drives the washer pump WP (pumpmotor) for a predetermined period. This feeds the cleaning liquid to thecleaning liquid intake passage 133 b from the washer pump WP through thecleaning liquid hose H1. Then, the cleaning liquid drawn from thecleaning liquid intake passage 133 b moves the cleaning-liquid-sidecheck valve 135 against the urging force and is supplied into the nozzlemember 9 (common intake chamber D). At this time, the cleaning liquidalso flows into the space SP located proximate to the basal flange 124 athrough a gap formed due to the loose fitting of the piston member 124and the inlet 122 d.

After stopping the washer pump WP (pump motor), the controller 81 drivesthe air pump AP (motor 43). Consequently, the air is fed to the airintake passage 131 e of the nozzle unit 106 from the air pump AP throughthe air hose H2 and then supplied into the nozzle member 109 (commonintake chamber D) from the air intake passage 131 e through the air-sidecheck valve 134. The air is mixed with the cleaning liquid stored in thecommon intake chamber D and ejected from the ejection ports 108 as thegas-liquid mixture. At this time, the mainstream of the fluid (air) islinearly directed to the distal end (ejection ports 108) of the nozzlemember 109 by the inlet 122 d. Additionally, a side stream of the fluid(air) also flows into the space SP located proximate to the basal flange124 a through the gap formed due to the loose fitting between the pistonmember 124 and the inlet 122 d. The feeding pressure moves the nozzlemember 109 frontward (refer to FIGS. 19, 24, and 25). Consequently, asshown in FIG. 17B, the ejection ports 108 of the nozzle member 109 aremoved to the cleaning position from the non-cleaning position toapproach the image capturing range center line X1 of the on-vehiclecamera 105. More specifically, as the fluid feeding pressure moves(frontward) the nozzle member 109, the fluid is ejected from theejection ports 108. This cleans the lens 105 b. FIG. 17B schematicallyshows the view shown on the display DSP and an ejection port 108 (distalportion of nozzle member 109) located in the image capturing range W.Also, FIG. 1B schematically shows an ejection port 108 (distal portionof nozzle member 109) located at the non-cleaning position outside theimage capturing range W indicated by double-dashed lines.

Then, the controller 81 again drives the air pump AP without driving thewasher pump WP (pump motor) so that only air is ejected. This feeds airfrom the air pump AP to the air intake passage 131 e through the airhose H2. As the air is supplied into the nozzle member 109 (commonintake chamber D) from the air intake passage 131 e through the air-sidecheck valve 134, the nozzle member 109 moves frontward (to the cleaningposition). Then, only air is ejected from the ejection ports 8. As aresult, the cleaning liquid, which was applied to the lens 5 b when thegas-liquid mixture was ejected, is blown away by the ejection of onlyair.

The second embodiment has the advantages described below.

(17) The nozzle member 109 is arranged to be movable so that theejection axis F of the fluid ejected from the ejection ports 108traverses the dividing center Y, which divides the lens 105 b (effectivesurface 105 c) into two. Thus, as compared to a nozzle member thatbecomes immovable when the ejection axis F reaches the dividing centerfrom one side of the dividing center Y (region close to nozzle member109), the other side of the dividing center Y (left side in FIG. 25(region distant from nozzle member 109)) may be cleaned in asatisfactory manner. Thus, a wide range of the lens 105 b may be cleanedin a satisfactory manner.

(18) The nozzle member 109 is arranged to be movable so that theejection axis F traverses the effective range Z1 (range corresponding toimage capturing range W), which extends from one end to the other end ofthe effective surface 105 c of the lens 105 b. Thus, the entireeffective range Z1 may be cleaned in a satisfactory manner.

(19) The effective surface 105 c corresponding to the image capturingrange W (refer to FIG. 25) is located on a central portion of the lens105 b. The nozzle member 109 is arranged to be movable so that theejection axis F traverses the lens range Z2, which extends from one endto the other end of the lens 105 b. Thus, the entire lens range Z2,which includes a periphery of the effective surface 105 c, may becleaned in a satisfactory manner.

(20) The nozzle member 109 ejects the fluid from the ejection ports 108as moved (frontward) by the fluid feeding pressure. This eliminates theneed of, for example, an electric driving device that moves the nozzlemember 109 and simplifies the structure.

(21) The nozzle member 109 is set so that the cleaning angle θ, which isformed by the ejection axis F and the tangent line of the lens 105 bwhere the cleaning liquid hits, is 22° or greater (in second embodiment,32°) based on the experimental results. Thus, the lens 105 b may becleaned in a further satisfactory manner (in which smudge is removedalmost completely).

(22) The nozzle member 109 is arranged to be capable of moving frontwardand rearward in a direction inclined relative to the image capturingrange center line X1 so that the ejection ports 108 approach the imagecapturing range center line X1 of the on-vehicle camera 105 when movedfrontward. Additionally, the ejection axis F is set to be inclinedinward from a direction orthogonal to the frontward-rearward movementdirection (frontward-rearward movement axis L1) of the nozzle member109. This reduces the lateral size (sideward direction in FIG. 20) ofthe device while cleaning in a satisfactory manner. More specifically,to clean in a satisfactory manner, the cleaning angle θ needs to beincreased (e.g., 22° or greater) as described above. If the ejectionaxis F extends in a direction orthogonal to the frontward-rearwardmovement direction (frontward-rearward movement axis L1) of the nozzlemember 109, the frontward-rearward movement direction of the nozzlemember 109 would need to be largely inclined relative to the imagecapturing range center line X1. This increases the lateral size of thedevice. In this regard, in the above configuration, the cleaning angle θmay be increased (e.g., 22° or greater) without greatly inclining thefrontward-rearward movement direction (frontward-rearward movement axisL1) of the nozzle member 109 relative to the image capturing rangecenter line X1. This reduces the lateral size of the device whilecleaning in a satisfactory manner.

(23) The cleaning-liquid-side check valve 135, which includes the valvemember 136 and the valve spring 137 that urges the valve member 136, isof a spring-type check valve. This prevents a leakage of the cleaningliquid from the cleaning liquid intake passage 133 b to the commonintake chamber D, for example, even when the vehicle starts to move orvibrates while traveling. Thus, a situation may be prevented in whichthe cleaning liquid is unintentionally leaked from the ejection ports108 and applied to the lens 105 b of the on-vehicle camera 105. Thespring-type check valve tends to be enlarged as compared to aduckbill-type check valve or the like. However, when this configurationis particularly applied to the present embodiment of the on-vehicleoptical sensor cleaning device, the enlargement may be limited in adirection orthogonal to the longitudinal direction of the cylinderhousing 121.

The second embodiment may be modified as follows.

In the second embodiment, the nozzle member 109 is arranged to bemovable so that the ejection axis F traverses the lens range Z2, whichextends from one end to the other end of the lens 105 b and includes theouter side of the effective surface 105 c corresponding to the imagecapturing range W (refer to FIG. 25). Instead, the ejection axis F maymove in a different range. The nozzle member 109 may be arranged to bemovable, for example, so that the ejection axis F traverses theeffective range Z1, which extends from one end to the other end of theeffective surface 105 c, but does not traverse the lens range Z2 (doesnot reach the further end of the lens 105 b (lens range Z2)).Alternatively, the nozzle member 109 may be arranged to be movable, forexample, so that the ejection axis F traverses the dividing center Y,which divides the lens 105 b into two, but does not traverse theeffective range Z1 (does not reach the further end of the effectiverange Z1).

In the second embodiment, the nozzle member 109 ejects the fluid fromthe ejection ports 108 as moved (frontward) by the fluid feedingpressure. Instead, for example, the fluid may be ejected from theejection ports 108 as the nozzle member 109 is moved (frontward) by anelectric driving device that is separately arranged.

In the second embodiment, the nozzle member 109 is set so that thecleaning angle θ, which is formed by the ejection axis F and the tangentline of the lens 105 b where the cleaning liquid hits, is 22° orgreater. More specifically, in the second embodiment, the cleaning angleθ is 32° when the ejection axis F reaches the further end of the lens105 b (refer to FIG. 25). However, the cleaning angle θ may be changedto a different angle.

In the second embodiment, the ejection axis F is set to be inclinedinward from a direction orthogonal to the frontward-rearward movementdirection (frontward-rearward movement axis L1) of the nozzle member109. However, the ejection axis F is not limited to this configurationand may be set, for example, in the direction orthogonal to thefrontward-rearward movement direction (frontward-rearward movement axisL1) of the nozzle member 109.

In the second embodiment, the controller 81 controls the air pump AP toeject only air after ejecting the gas-liquid mixture. Instead, thecontrol may be terminated when the gas-liquid mixture is ejected withoutthe ejection of only air. Additionally, for example, when a liquid suchas raindrops is applied to the lens 5 b, only air may be ejected withoutthe ejection of the gas-liquid mixture.

In the second embodiment, the on-vehicle optical sensor unit 103 isarranged on the rear door 2. However, the on-vehicle optical sensor unit103 may be arranged on any position of a rear portion of the vehicle 1.Further, the on-vehicle optical sensor unit 103 may be arranged on afront portion or a side portion (near door mirror) of the vehicle 1.

The present examples and embodiments are to be considered asillustrative and not restrictive, and the invention is not to be limitedto the details given herein, but may be modified within the scope andequivalence of the appended claims.

The invention claimed is:
 1. An on-vehicle optical sensor cleaningsystem comprising: a washer pump that feeds a cleaning liquid; an airpump that includes a discharge valve and discharges air through thedischarge valve, wherein the discharge valve opens when air iscompressed in the air pump; a nozzle member including an ejection portthat ejects a gas-liquid mixture toward a sensing surface of anon-vehicle optical sensor to remove foreign matter from the sensingsurface, wherein the cleaning liquid from the washer pump and the airfrom the air pump are mixed in the gas-liquid mixture; and a controllerthat controls the washer pump and the air pump, wherein the nozzlemember includes a common intake chamber located therein, wherein thecommon intake chamber is in communication with the ejection port andcapable of drawing in the cleaning liquid and the air, and thecontroller is configured so that the gas-liquid mixture is ejected bystoring the cleaning liquid in the common intake chamber to cover theejection port and then feeding the air to the nozzle member.
 2. Theon-vehicle optical sensor cleaning system according to claim 1, whereinthe controller controls the air pump so that after the gas-liquidmixture is ejected, only air is ejected.
 3. The on-vehicle opticalsensor cleaning system according to claim 1, further comprising acylinder housing that accommodates the nozzle member, wherein the nozzlemember is capable of moving frontward and rearward in the cylinderhousing, the nozzle member includes a distal portion provided with theejection port, and the nozzle member is urged and moved forward byfeeding pressure of the air.
 4. The on-vehicle optical sensor cleaningsystem according to claim 1, further comprising: a cleaning liquidintake passage that draws in the cleaning liquid; an air intake passagethat draws in the air; a cleaning-liquid-side check valve; and anair-side check valve, wherein the nozzle member includes a distalportion provided with the ejection port, the common intake chamber iscapable of drawing in the cleaning liquid and the air through thecleaning liquid intake passage and the air intake passage, thecleaning-liquid-side check valve is located between the cleaning liquidintake passage and the common intake chamber, and the air-side checkvalve is located between the air intake passage and the common intakechamber.
 5. The on-vehicle optical sensor cleaning system according toclaim 4, further comprising an inlet member configured to communicate adownstream side of the cleaning-liquid-side check valve and a downstreamside of the air-side check valve, wherein the inlet member includes atubular inlet that is loosely fitted to an inner circumferential surfaceof the nozzle member from a basal end of the nozzle member.
 6. Theon-vehicle optical sensor cleaning system according to claim 4, furthercomprising: a spring holder; and a compression coil spring, wherein thenozzle member includes a piston nozzle member and a flange member, thepiston nozzle member includes a tube and a nozzle, wherein the nozzle isbulged radially outward from a distal portion of the tube and includes adistal end that defines the ejection port, the flange member includes abasal flange and is fixed to a basal end of the piston nozzle member,the spring holder is configured to be fitted onto the tube and allow foraxial sliding of the tube, the compression coil spring is fitted ontothe tube and held in a compressed state between the spring holder andthe basal flange, the nozzle member, the spring holder, and thecompression coil spring are coupled to assemble a piston unit; thepiston unit, which has been assembled, is inserted into and coupled to acylinder housing from a basal end of the cylinder housing, wherein thecylinder housing is configured to accommodate the piston unit, thenozzle projects out of a distal portion of the cylinder housing, and thespring holder engages with the distal portion of the cylinder housing torestrict further movement of the spring holder.
 7. The on-vehicleoptical sensor cleaning system according to claim 6, further comprisinga lip packing, wherein the basal flange of the nozzle member includes apacking fitting recess that extends throughout the circumference andopens radially outward, the lip packing includes an annular fittingportion that is fitted to the packing fitting recess and a slide portionthat slides on an inner circumferential surface of the cylinder housing,the packing fitting recess includes a separation restriction groove thataxially extends, and the fitting portion includes a separationrestriction projection that is fitted to the separation restrictiongroove.
 8. The on-vehicle optical sensor cleaning system according toclaim 4, wherein the cleaning-liquid-side check valve and the air-sidecheck valve are arranged next to each other in a longitudinal directionof the nozzle member.
 9. The on-vehicle optical sensor cleaning systemaccording to claim 4, wherein the cleaning-liquid-side check valve is aspring-type check valve and includes a valve member and a valve springthat urges the valve member.
 10. The on-vehicle optical sensor cleaningsystem according to claim 1, wherein the nozzle member is movable sothat an ejection axis of a fluid ejected from the ejection porttraverses a dividing center that divides the sensing surface into twofrom one side to the other side, and the fluid is one of the cleaningliquid, the air, and the gas-liquid mixture.
 11. The on-vehicle opticalsensor cleaning system according to claim 1, wherein the nozzle memberis movable so that an ejection axis of a fluid ejected from the ejectionport traverses an effective range extending from one end to the otherend of an effective surface of the sensing surface, and the fluid is oneof the cleaning liquid, the air, and the gas-liquid mixture.
 12. Theon-vehicle optical sensor cleaning system according to claim 1, whereinthe nozzle member is capable of moving frontward and rearward in adirection inclined relative to an image capturing range center line ofthe on-vehicle optical sensor, the nozzle member is configured so thatthe ejection port approaches the image capturing range center line whenthe nozzle member is urged and moved forward by feeding pressure of theair, an ejection axis of a fluid ejected from the ejection port is setto be inclined inward from a direction orthogonal to afrontward-rearward movement direction of the nozzle member, and thefluid is one of the cleaning liquid, the air, and the gas-liquidmixture.
 13. The on-vehicle optical sensor cleaning system according toclaim 1, further comprising an on-vehicle optical sensor attachmentbracket including a sensor receptacle and a nozzle receptacle that areformed integrally with each other, wherein the sensor receptacleaccommodates the on-vehicle optical sensor so that the sensing surfaceis exposed to the exterior, the nozzle receptacle is configured toaccommodate a nozzle unit that includes the nozzle member, the nozzlemember is configured to be capable of moving frontward and rearward to anon-cleaning position and a cleaning position, the nozzle member isconfigured to eject a fluid from the ejection port toward the sensingsurface when the nozzle member is moved to the cleaning position fromthe non-cleaning position and projected out of the nozzle receptacle,and the fluid is one of the cleaning liquid, the air, and the gas-liquidmixture.
 14. The on-vehicle optical sensor cleaning system according toclaim 13, wherein the on-vehicle optical sensor attachment bracketincludes a liquid release portion capable of receiving the cleaningliquid at a location corresponding to the ejection port of the nozzlemember when located at the non-cleaning position.
 15. The on-vehicleoptical sensor cleaning system according to claim 1, wherein the airpump includes a tubular cylinder, a piston that is movable forward andbackward in the cylinder, a motor located at a backward movement side ofthe piston, wherein the motor drives the piston forward and backward,the discharge valve that includes a discharge valve port and operates toopen and close the discharge valve port, wherein inner and outer sidesof the cylinder are in communication through the discharge valve port,and a suction valve that includes a suction valve port and operates toopen and close the suction valve port, wherein the inner and outer sidesof the cylinder are in communication through the suction valve port,when the piston moves forward to reduce space in the cylinder, the airis compressed in the cylinder and the discharge valve opens anddischarges the compressed air from the discharge valve port, when thepiston moves backward, the suction valve opens and draws air into thecylinder from the suction valve port, the suction valve port is anopening of a piston communication bore located in the piston, and thesuction valve port is in communication with the exterior through thepiston communication bore and an external communication bore located ina housing for the motor.
 16. The on-vehicle optical sensor cleaningsystem according to claim 4, wherein the nozzle member, the cleaningliquid intake passage, the air intake passage, the cleaning-liquid-sidecheck valve, and the air-side check valve form a nozzle unit.
 17. Theon-vehicle optical sensor cleaning system according to claim 1, whereinthe ejection port has a first cross-sectional area extending in adirection perpendicular to an ejection direction of the gas-liquidmixture, the common intake chamber has a second cross-sectional areaextending in a direction perpendicular to a longitudinal direction ofthe nozzle member, and the first cross-sectional area is smaller thanthe second cross-sectional area.
 18. The on-vehicle optical sensorcleaning system according to claim 1, wherein the nozzle member furtherincludes a bent portion located at a distal side of the nozzle member,and the bent portion is bent so that an ejection axis forms an acuteangle with an axis of the common intake chamber along a direction inwhich the gas-liquid mixture flows.